This invention relates to a radio communication apparatus, such as a portable telephone set with a radio paging function, for use in a portable telephone system such as a mobile telephone system and in a radio paging system.
A conventional radio communication apparatus of the type described comprises a portable telephone portion for carrying out mutual communication with a portable telephone base station, a radio paging portion responsive to a radio paging signal for carrying out call announcement in a tone generation mode, call announcement in a silent mode, and display announcement of a message, and a display unit for displaying reception information of the radio paging signal.
Examples of the conventional radio communication apparatus are disclosed in Published Japanese Patent Applications Nos. 294645/1992 and 64133/1991.
The radio communication apparatus is adapted for use in a portable telephone system and a radio paging system independent from each other. Even at a position beyond a communication area of the portable telephone system, a radio paging operation can be carried out. Upon reception of a radio paging operation outside the communication area of the portable telephone system, a user of such radio communication apparatus moves into the communication area of the portable telephone system and then contacts, by the use of the portable telephone function of the radio communication apparatus, a person who initiates the radio paging operation.
Each of the conventional radio communication apparatus described above carries out call announcement (radio paging operation) every time upon reception of a radio paging signal coincident with a paging number assigned thereto (hereinafter referred to as reception of a radio paging operation), irrespective of whether or not a portable telephone function is used, namely, whether or not the radio communication apparatus is in a communication state. Accordingly, when the radio communication apparatus is within a communicable area of a portable telephone base station of the portable telephone system, call announcement by the radio paging function can be made during communication by the portable telephone function. However, during communication by the portable telephone function, generation of a tone for call announcement results in hindrance of communication.